The invention concerns a filtering apparatus which includes a housing in which several parallel filter elements are placed. One end of each filter element is fastened to a housing partition wall, and the other end is attached by means of an axially projecting threaded spindle element to a support member mounted in the housing.
Such a filtering apparatus serves, for example, to filter solids and/or water from liquids such as fuels and other liquid carbohydrates. A field of application which poses particularly high requirements for these filters is the purification of aircraft fuels. For this purpose stationary or mobile filters are used, which must provide a very high degree of separating and trapping actions.
In the usual configuration of these filters several separator and trapping elements are located in a generally cylindrical housing, which hereafter will be referred to as filter elements. These filter elements are fastened at one end, i.e., an end that is provided with an inlet opening, to a partition wall of the housing. The partition separates a clean chamber from a sediment chamber of the housing.
The usually long and slender filter elements must also be supported at their other ends. For this purpose, a threaded member is used which, for example, is in the form of a center spindle projecting from the end of the filter element. The spindle may extend entirely through the filter element to fasten the filter element to the housing partition and to clamp together the end flanges of the filter element.
At the end facing away from the partition wall this spindle protrudes and is fastened to a structural part such as an end wall, spider or grid, which, in turn, is secured to the inside of the cylindrical wall of the housing.
In the course of the installation of the filtering apparatus and the replacement of filter elements, the spider is installed and fastened last, following the mounting of the filter elements. Often, the mounting means on the partition wall which receives one end of the filter element is not properly aligned with the opposing bore in the spider that is to receive the projecting end of the spindle. Thus, it may be necessary to bend the filter element so that it properly mates with the spider. The deformations incurred in this manner could result in damage to the filter elements or to a seal which seals the filter element relative to the partition wall.
To remedy this problem, a known filtering apparatus of the above-mentioned type, e.g., see U.S. Pat. No. 4,340,476 (corresponding to German Patent No. 30 24 106), has the filter element mounted on the partition wall in a non-rigid manner, without affecting the sealing action in this location. It is made possible in this manner to displace the opposite free ends of the filter elements during installation, until they fit into the receiving bores of the spider. To facilitate the process, the receiving bores may be shaped conically. However, the overall installation is made more difficult in that the threaded spindles of all of the filter elements must be aligned and introduced simultaneously into the receiving bores of the spider.
This problem also exists in another known form which it is possible to individually set the receiving bores on an end wall to adapt to filter elements rigidly connected with the partition wall. The end wall is in the form of a plate containing circular disks associated with respective filter elements. Each disk is held rotatably in the plate and contains the receiving bore into which the threaded spindle of the respective filter element is to be inserted. The receiving bore is in the form of a linear elongated slot formed in the circular disk in a diametrical direction. By rotating the disk and shifting the threaded spindle within the elongated slot, the fastening location for a given filter element may be aligned with the end of the threaded spindle.
This arrangement is relatively complicated. In addition, it disadvantageously requires that all of the spindle elements be introduced simultaneously into the elongated slots of the spider.
It is, therefore, an object of the invention to provide a filtering apparatus of the afore-described type which makes it possible by means of a simple structural configuration of the spider to mount each filter element successively and separately, whereby alignment relative to the position of the free end of the individual filter elements could be achieved in a simple manner.